Ribbon feed mechanism for feeding type ribbon on type ribbon spools

ABSTRACT

A printing apparatus having an electrically controlled carrier assembly for driving drive spools which engage type ribbon spools used for winding type ribbon from one type ribbon spool to another. The carrier assembly drives one of the drive spools in one direction winding ribbon on the ribbon spool. When the ribbon spool has been unwound from the opposite ribbon spool, the apparatus receives an electrical signal. The carrier assembly then disengages the drive spool, rotates and drives the other drive spool in an opposite direction. This operation is repeated continuously as the apparatus winds the ribbon from one ribbon spool to the other.

United States Patent [191 Eckerd et al.

[ RIBBON FEED MECHANISM FOR FEEDING TYPE RIBBON ON TYPE RIBBON SPOOLS[75] Inventors: Steve S. Eckerd; Ivan N. Markowitz;

Anthony F. Maggio, all of Oklahoma City; Darby A. Gray, Norman, all ofOkla.

[73] Assignee: Honeywell Information Systems,

Inc., Waltham, Mass.

[22] Filed: June 3, 1974 [21] Appl. No.: 475,550

{52] US. Cl. 242/67.4 [51] Int. CI. 8651-! 17/02 [58] Field of Search242/67.4, 20]; 197/160 [56] References Cited UNITED STATES PATENTS2,583,385 l/l952 Miller 242/67.4 3,632.052 l/l972 Read 3.722,822 3/1973Wallace 242/67.4

FOREIGN PATENTS OR APPLICATIONS 849.858 8/l939 France 242/67.4

[ 5] Dec. 2, 1975 350,690 7/l937 Italy 242/67.4

Primary Examiner-Edward J. McCarthy Attorney. Agent, or FirmR0nald T.Reiling [5 7] ABSTRACT A printing apparatus having an electricallycontrolled carrier assembly for driving drive spools which engage typeribbon spools used for winding type ribbon from one type ribbon spool toanother. The carrier assembly drives one of the drive spools in onedirection winding ribbon on the ribbon spool. When the ribbon spool hasbeen unwound from the opposite ribbon spool, the apparatus receives anelectrical signal. The carrier assembly then disengages the drive spool,rotates and drives the other drive spool in an opposite direction. Thisoperation is repeated continuously as the apparatus winds the ribbonfrom one ribbon spool to the other.

5 Claims, 2 Drawing Figures US. Patent Dec. 2, 1975 Sheet 1 of 23,923,267

US. Patent Dec. 2, 1975 Sheet 2 of2 3,923,267

N 0% 90 0% WM bk Wm mm E. 3 2w mm 3 m@ ov\m mm 3 .2

QM wm Nv mw RIBBON FEED MECHANISM FOR FEEDING TYPE RIBBON ON TYPE RIBBONSPOOLS BACKGROUND OF INVENTION This invention relates generally toimprovements in a printing apparatus and more particularly, but not byway of limitation, to a ribbon feed mechanism for electricallycontrolling a carrier assembly used in winding ribbon from one ribbonspool to'another ribbon spool.

In a prior art printing apparatus, the ribbon feed mechanism uses anoperation of advancing and reversing ribbon by using drive spools withratchet teeth. An actuator arm is spring-biased against one drive spooland is moved back and forth by a solenoid. A stop is spring-biasedagainst the ratchet teeth of the ribbon spool so that the spool rotatesonly on the forward stroke of the actuator arm. When the end of theribbon is reached, a wiper drops from the undriven ribbon spool. Thewiper rotates into the path of the moving actuator arm and acts as afulcrum for the actuator arm to pivot about on the return stroke. Theactuator arm then pivots against the opposite drive spool and beginsdriving it. The ribbon then advances inthe opposite direction pullingthe wiper back into the ribbon spool.

SUMMARY OF INVENTION The present invention has no cams, slides,followers, overcenter mechanisms, or ratchet assemblies which arecharacteristic of the presently used ribbon feed mechanisms. Theelimination of these characteristics, mechanical components and thesubstitution of electrical controls result in a more reliable ribbonfeed mechanism which can be used in high speed printing apparatus.

The improved printing apparatus includes a base plate, a type ribbonwound on type ribbon spools, a first drive spool and a second drivespool engaging the ribbon spools for winding the ribbon from one ribbonspool to the other ribbon spool, a carrier assembly for engaging androtatably driving the first drive spool, disengaging the drive spool andengaging and rotatably driving the second drive spool, an electric motorhaving a motor shaft rotatably driving said carrier assembly, and acontact board in contact with the first drive spool and the second drivespool for electrically signaling the motor when the ribbon on the ribbonspool is unwound so that the direction of rotation of the motor shaft isreversed, thereby reversing the' direction of rotation of the carrierassembly.

Advantages and objects of the invention will be evident from thefollowing detailed description when read in conjunction with theaccompanying drawings which illustrate an embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of theimproved printing apparatus. r

FIG. 2 is a cross-section of a side view of the carrier assembly anddrive spool.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 the printingapparatus is designated by a general reference character 10. Apparatusincludes a type ribbon cartridge 12 which is seated on a first drivespool 14 and a second drive spool 16, a carrier assembly 17 for drivingthe first drive spool 14 and the second drive spool 16, a base plate 18,a ribbon guide 20 pivotally attached to the base plate 18, a switchassembly 22 attached to the base plate 18 and electrically connected toa motor 24. The motor 24 has a motor shaft 26 attached to the carrierassembly 17.

The type ribbon cartridge 12 includes a type ribbon 28 attached to typeribbon spools 30. The spools 30 have centering notches 32 at the bottomportion thereof. The cartridge 12 also includes apertures 34 into whichthe first drive spool 14 and the second drive spool 16 are inserted.Centering notches 32 serve to properly align the type ribbon spools 30on the first drive spool 14 and the second drive spool 16.

The carrier assembly 17 includes a carrier housing 36 containing apinion gear 38 which is attached to'the motor shaft 26. The pinion gear38 drives a first planet gear 40 and a second planet gear 42. Secured tothe top of the planet gears are thrust washers 44.

The first drive spool 14 and the second drive spool 16 include annularbase 46 with a cylindrical housing 48 attached to a center portionthereof. The annular base 46 includes an aperture 47, a notched shoulder52 around the circumference of the base 46, and gear teeth 54 adjacentto the shoulder 52. The housing 48 is rotatably mounted on a post 51which is secured to the base plate 18. The housing 48 includes a slot 49therein, and a centering ramp 50 which engages the centering notches 32of the ribbon spools 30 whenthe ribbon cartridge 12 is attached thereto.A spring-biased wiper 56 positioned inside aperture 47 and slot 49 ispivotally secured to post 51.

The switch assembly 22 includes a contact board 58 secured to the baseplate 18 and positioned between the plate 18 and the drive spools. Theboard 58includes pear shaped electrical contact pads 60 which arepreferably gold plated copper conductors. The pads 60 are positionedunderneath the apertures 47 and around the circumference of the drivespools so that when wiper 56 drops through the aperture 47 it willcontact the pad 60. At the neck of the pear shaped pads 60 are solderingposts 62 for connecting electrical circuitry used to signal the motor24. The electrical circuitry is not shown in this figure.

FIG. 2 is a more detailed drawing of a cross-section of the carrierassembly 17 engaging the first drive spool 14. The bottom line of theribbon cartridge 12 is shown in its proper position when seated on thedrive spool, but the ribbon 28 and the ribbon spools 30 are not shown.

Motor shaft 26, of the motor 24, is shown secured to the pinion gear 38which is held in place by a retaining ring 64. The pinion gear 38 isshown meshing with the first planet gear 40 at a position 66. The firstplanet gear 40 is held in the carrier housing 36 by planet pin 68 andengages the gear teeth 54 of the first drive spool 14 at a position 69.

The drive spool 14 is shown secured to the post 51 by retaining ring 70.The wiper 56 is positioned inside the slot 49 of the housing 48 andinside aperture 47 of the base 46. The wiper 56 includes a vertical arm72 and a horizontal arm 74. The vertical arm has a finger 76 whichextends outwardly from the slot 49. The horizontal arm 74 includes anend portion 78 which is bent at right angles to the arm 74. One end of awiper spring 80 is positioned parallel to the arm 74, rests on the endportion 78 and biases the arm 74 downward toward the contact pad 60. Thewiper 56 is pivotally attached to the post 51 by a wiper pivot pin 82. Abottom portion 84 of the arm 74 is used to contact the pads 60. The

contact pads 60 are shown as part of the top of the contact board 58.

Operation In operation, the electrically controlled ribbon feedmechanism works as follows.

The ribbon cartridge 12 is seated on the first drive spool 14 and thesecond drive spool 16. The housings 48 are inserted into the ribbonspools 30 aided by the centering ramps 50 and the centering notches 32.As the cartridge 12 is inserted, the ribbon 28 being wrapped around theribbon spools 30 comes into contact with the finger 76 of the wiper 56.The wiper 56 being pivotally mounted and positioned inside the aperture47 and slot 49 is forced further back into the slot 49 as the ribbon 28bares against the finger 76. When the cartridge 12 is seated on top ofthe drive spools and the ribbon 28 is properly positioned on the ribbonguide 20, the printing apparatus is then ready to be used.

Using the illustration in FIG. 1, it can be seen that if the ribboncartridge 12 is seated on the drive spools, theribbon spool 30 attachedto the first drive spool 14 has been unwound. The wiper 56 beingspring-biased has dropped through aperture 47 and is in contact with thecontact pad 60, sending an electrical signal to the electricalcircuitryto tell the motor 24 to rotate the carrier assembly 17.

The motor shaft 26 rotates the carrier assembly 17 toward the firstdrive spool 14. The first planet gear 40 engages the first drive spool14 and begins driving it. At this time, thrust washer 44 engages thenotched shoulder 52 of the drive spool 14, maintaining the gear teethalignment along the pitc'hline. As the spool 14 turns, the ribbon 28begins to wind around the ribbon spool 30. The ribbon contacts thefinger 76 and forces the wiper 56 back .into the slot 49 thus pivotingthe horizontal arm 74 upward and away from the contact pad 60 and intothe aperture 47.

The drive spool 14 continues to wind the ribbon 28 on the ribbon spool30 until the ribbon 28 is unwound from the opposite spool 30. The wiper56 in the unwound spool 30, now drops through the aperture 47 of thesecond drive spool 16 and contact is made with the contact pad 60,transmitting the electric signal to the circuitry which controls motor24. When the motor 24 receives a reversing signal, the motor shaft 26disengages the carrier assembly 17 from the first drive spool 14. androtates the carrier assembly 17 toward the second drive spool 16. Thesecond planet gear 42 now engages the second drive spool 16 and beginsdriving it in the opposite direction. As the spool 16 turns, the ribbonbegins to wind onto the ribbon spool 30 and the finger 76 of the wiper56 is forced back into the slot 49. The drive spool 16 continues to windthe ribbon 28 on the ribbon spool 32 until the ribbon is unwound fromthe other spool 32. The operation then repeats itself.

Changes may be made in the construction and arrangement of parts orelements of the various embodiments as disclosed herein withoutdeparting from the spirit and scope of the invention as defined in thefollowing claims.

What is claimed is:

1. In a printing apparatus having a base plate, a type ribbon wound ontype ribbon spools, afirst drive spool and a second drive spool engagingthe ribbon spools for winding the ribbon from one ribbon spool to theother ribbon spool, the improvement comprising:

drive means for engaging and rotatably driving the first drive spool,disengaging the first drive spool, engaging and rotatably driving thesecond drive spool;

an electric motor having a motor shaft rotatably driving said drivemeans; and

an electrical contact board disposed between the base plate and thefirst and second drive spools, and electrically connected to said motor,said electrical contact board in contact with the first drive spool andthe second drive spool for producing an electrical signal when theribbon on the ribbon spool is unwound so that the direction of rotationof the motor shaft is reversed, thereby reversing the direction ofrotation of said drive means.

2. The apparatus as defined in claim 1 wherein said drive means is acarrier assembly comprising:

a carrier housing;

a pinion gear attached to said housing and rotatably driven by saidmotor shaft;

a first planet gear attached to said housing and rotatably driven bysaid pinion gear; and

a second planet gear attached to said housing and rotatably driven bysaid pinion gear.

3. The apparatus as defined in claim 2 wherein rotation of the motorshaft in one direction pivots said first planet gear on said carrierassembly into driving engagement with said first drive spool, whereasrotation of the motor shaft in the other direction pivots said secondplanet gear on said carrier assembly into driving engagement with saidsecond drive spool.

4. The apparatus as defined in claim 3 wherein said first planet gearand second planet gear include thrust washers secured thereto, saidwashers having a greater diameter than said first and second planetgears so that when said'first and second planet gears mesh with saidfirst and second drive spools, said thrust washers engage said drivespools aligning the meshing gear teeth along the proper pitchline.

5. In a printing apparatus having a base plate, a type ribbon wound ontype ribbon spools, a first drive spool and a second drive spoolengaging the ribbon spools for winding the ribbon from one ribbon spoolto the other ribbon spool, the drive spools housing spring-biased wiperswhich are held in place by the ribbon as it is wrapped around the ribbonspools, the improvement comprising:

a carrier assembly for engaging and rotating the first drive spool,disengaging the first drive spool, engaging and rotating the seconddrive spool, the assembly comprising: a a carrier housing;

a pinion gear attached to said housing;

a first planet gear attached to said housing and rotatably driven bysaid pinion gear, said first planet gear engaging and rotatably drivingthe first drive spool;

a second planet gear attached to said housing and rotatably driven bysaid pinion gear, said second planet gear engaging and rotatably drivingthe second drive spool;

an electric motor having a motor shaft rotatably driving said piniongear; and

motor so that the direction of rotation of said motor shaft is reversedthereby reversing the direction of rotation of said carrier assembly.

l l l

1. In a printing apparatus having a base plate, a type ribbon wound ontype ribbon spools, a first drive spool and a second drive spoolengaging the ribbon spools for winding the ribbon from one ribbon spoolto the other ribbon spool, the improvement comprising: drive means forengaging and rotatably driving the first drive spool, disengaging thefirst drive spool, engaging and rotatably driving the second drivespool; an electric motor having a motor shaft rotatably driving saiddrive means; and an electrical contact board disposed between the baseplate and the first and second drive spools, and electrically connectedto said motor, said electrical contact board in contact with the firstdrive spool and the second drive spool for producing an electricalsignal when the ribbon on the ribbon spool is unwound so that thedirection of rotation of the motor shaft is reversed, thereby revErsingthe direction of rotation of said drive means.
 2. The apparatus asdefined in claim 1 wherein said drive means is a carrier assemblycomprising: a carrier housing; a pinion gear attached to said housingand rotatably driven by said motor shaft; a first planet gear attachedto said housing and rotatably driven by said pinion gear; and a secondplanet gear attached to said housing and rotatably driven by said piniongear.
 3. The apparatus as defined in claim 2 wherein rotation of themotor shaft in one direction pivots said first planet gear on saidcarrier assembly into driving engagement with said first drive spool,whereas rotation of the motor shaft in the other direction pivots saidsecond planet gear on said carrier assembly into driving engagement withsaid second drive spool.
 4. The apparatus as defined in claim 3 whereinsaid first planet gear and second planet gear include thrust washerssecured thereto, said washers having a greater diameter than said firstand second planet gears so that when said first and second planet gearsmesh with said first and second drive spools, said thrust washers engagesaid drive spools aligning the meshing gear teeth along the properpitchline.
 5. In a printing apparatus having a base plate, a type ribbonwound on type ribbon spools, a first drive spool and a second drivespool engaging the ribbon spools for winding the ribbon from one ribbonspool to the other ribbon spool, the drive spools housing spring-biasedwipers which are held in place by the ribbon as it is wrapped around theribbon spools, the improvement comprising: a carrier assembly forengaging and rotating the first drive spool, disengaging the first drivespool, engaging and rotating the second drive spool, the assemblycomprising: a carrier housing; a pinion gear attached to said housing; afirst planet gear attached to said housing and rotatably driven by saidpinion gear, said first planet gear engaging and rotatably driving thefirst drive spool; a second planet gear attached to said housing androtatably driven by said pinion gear, said second planet gear engagingand rotatably driving the second drive spool; an electric motor having amotor shaft rotatably driving said pinion gear; and an electricalcontact board disposed between the base plate and the first and seconddrive spools, the wiper contacting said board when the ribbon on theribbon spool is unwound to electrically signal said motor so that thedirection of rotation of said motor shaft is reversed thereby reversingthe direction of rotation of said carrier assembly.